Design And Application Of Wildflower Strip

Wildflower strip,which constructed on the margin of cropland,orchard,vegetable plot,roadside,waterfront,etc.by means of mixed sowing,through the configuration of different functional plants to form community performs an important ecosystem service for improving the efficiency of crop pollination and controlling pests.It can provide pollinators and natural enemies with nectar and pollen resources and shelters,improve the quality of urban habitats,strengthen the support system of natural enemies,reduce the use of pesticides,restore soil,purify water,inhibit weeds,etc.in the urban and rural area.At present,the application and policy-setting of wildflower strip are mainly concentrated in the developed countries of Europe and the United States,which apply it under ecological compensation mechanism;Many developing countries are still in the early stage of development and lack of practical application.In order to figure out of the basics of application of wildflower strip in China,the diversity distribution of arthropod species,natural enemies,pollinators,pests and neutral insects in different wildflower meadows,and the dynamics were studied through the community quadrat investigation in non-crop habitats of Beijing suburb and experimental base.The relationship between structure and functional groups of arthropods,the relationship between flowering phenology and functional groups of arthropods,the feeding range of pollinators in the community and the common food source of different groups,the importance of different nectar and pollen plants for different arthropods,and the correlation between key functional traits of plants such as flower color and flower amount related to the species richness of arthropods were analyzed.The study laid a practical foundation for the development of wildflower strip in China,and opened up a precedent for the conservation,restoration and design of biological diversity in non crop habitats.The main results are as follows:In the non-crop habitats of Beijing suburb,633 plots of 25 sampling sites were set up,and 204 species of herbaceous plants belonging to 152 genera,51 families were investigated.Plant diversity is different in different non-crop habitats of farmlands.The diversity of herbaceous plants in non-crop habitat is the highest in the shallow mountain area and the deep mountain area,which is mainly composed of the native plants,while the cultivated plants are dominant in the outskirts.In the woodland and forest edge habitat,61% of the investigated samples were the moderate disturbance wild plant communities;in the field ridge and adret habitat,56% of the investigated samples were mainly the moderate disturbance wild plant communities;in the road and homestead habitats,the cultivated plants accounted for 72%;in the waterfront habitats,40% were mainly the low disturbance wild plant communities.A total of 14691 pollinators,belonging to 29 genera,20 families and 5 orders,were observed in all the plots,among which Apis cerana was the main pollinator,and the pollinator had the highest average frequency of visiting flowers for Inula japonica,Patrinia scabiosifolia,Galium verum and Gypsophila oldhamiana.These four kinds of plants are the most valuable for pollinator conservation.There are 8 former plots,1 designed plot and 27 quadrats in the experimental base of wildflower strip.There are 42 species,38 genera and 20 families of plants.And 2 classes,10 orders,65 families,100 genera and 109 species of arthropods are accounted in 10 surveys.In the experiment,the wildflower strip can accommodate 25 kinds of natural enemies,21 kinds of pollinators and 9 kinds of pests.In terms of dynamics,66.7% of the mixed communities reached the maximum of plant species number and diversity index in May.At this time,there was a strong correlation between pollinator functional groups and plant species richness.After May,there was no significant difference between the dynamics of dominant species of pollinators in each community.A.mellifera and A.cerana occupied the position of core pollinators in all season.Firstly,the diversity of pollinators increased and then decreased,while the diversity of natural enemies and pests decreased slightly in May and reached the peak in July to August,which was probably related to the coverage of wildflower strips.Based on the pollinators,it was found that the nectar,the tubular corolla and the radiation symmetrical flowers plants were used by the most pollinator groups,among which the social bees had the largest feeding range,the niche breadths reached to 14.97,and 25 kinds of insectary plants were found,among which the dominant species was the A.mellifera,which used the Dalea purpurea in the wildflower strip.The individual feeding ratio was as high as 0.11.Flies and social bees shared 23 kinds of food,accounting for 92% of the total species of insectary plants in all observation periods.Flies prefer white flowers,social bees and syrphids prefer yellow and blue-purple flowers,butterflies prefer red,especially pink pollen plants,such as Oenothera speciosa,etc.Large flowers attract more social bees and syrphids,while small flowers are mostly large flowers,which are more favored by Lepidoptera such as butterflies,skippers and moths.In the non-crop habitat of Beijing suburb,cultivated plants and native plants have important protection and application value for pollinator conservation.The investigation in the experimental site also verified that plant diversity can help to improve the diversity of arthropod functional groups such as pollinators,and key functional traits such as flower color and flower amount can also be applied to the screening of plants for wildflower strip in the non-crop habitat.According to the temporal and spatial dynamics of functional groups of different arthropods,the optimal plant community structure can be determined,and the continuous food supply can be realized.In terms of the function group of pollinators,the species of plants are single in summer and autumn,and the structure of pollination network is not stable in Chaoyang and Changping outskirts.The designed wildflower strip provides a continuous supply of diverse food sources for pollinators,and has a strong pollination service function.Therefore,the wildflower strip can be selected as the initial target for non-crop habitat in the outskirts.